| // SPDX-License-Identifier: GPL-2.0 |
| // Test shifting of newly-SACKed ranges onto the previous already-SACKed skb. |
| // This variant tests the case where we mark packets 0-4 lost, then |
| // get a SACK for 3, and then a SACK for 4. |
| |
| `./defaults.sh` |
| |
| // Establish a connection and send 10 MSS. |
| 0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3 |
| +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0 |
| +0 bind(3, ..., ...) = 0 |
| +0 listen(3, 1) = 0 |
| |
| +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 7> |
| +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8> |
| +.1 < . 1:1(0) ack 1 win 1024 |
| +0 accept(3, ..., ...) = 4 |
| |
| +0 write(4, ..., 10000) = 10000 |
| +0 > P. 1:10001(10000) ack 1 |
| |
| // SACK for 7001:8001. Using RACK we delay the fast retransmit. |
| +.1 < . 1:1(0) ack 1 win 257 <sack 7001:8001,nop,nop> |
| // RACK reordering timer |
| +.027 > . 1:1001(1000) ack 1 |
| +0 %{ |
| assert tcpi_ca_state == TCP_CA_Recovery, tcpi_ca_state |
| assert tcpi_lost == 7, tcpi_lost # RACK thinks 1:7001 are lost |
| assert tcpi_reordering == 3, tcpi_reordering |
| }% |
| |
| // SACK for 3001:4001. |
| +.002 < . 1:1(0) ack 1 win 257 <sack 3001:4001 7001:8001,nop,nop> |
| +0 > . 1001:2001(1000) ack 1 |
| +0 %{ |
| assert tcpi_lost == 6, tcpi_lost # since 3001:4001 is no longer lost |
| assert tcpi_reordering == 5, tcpi_reordering # 7001:8001 -> 3001:4001 |
| }% |
| |
| // SACK for 4001:5001. |
| // This SACK for an adjacent range causes the sender to |
| // shift the newly-SACKed range onto the previous skb. |
| // It uses the RFC3517 algorithm to mark 1:3001 lost |
| // because >=3 higher-sequence packets are SACKed. |
| +.002 < . 1:1(0) ack 1 win 257 <sack 3001:5001 7001:8001,nop,nop> |
| +0 > . 2001:3001(1000) ack 1 |
| +0 %{ |
| assert tcpi_lost == 5,tcpi_lost # SACK/RFC3517 thinks 1:3001 are lost |
| }% |
| |
| // SACK for 8001:9001. |
| +.002 < . 1:1(0) ack 1 win 257 <sack 3001:5001 7001:9001,nop,nop> |
| |
| // SACK for 9001:10001. |
| +.002 < . 1:1(0) ack 1 win 257 <sack 3001:5001 7001:10001,nop,nop> |
| +0 > . 5001:6001(1000) ack 1 |
| |
| // To simplify clean-up, say we get an ACK for all data. |
| +.1 < . 1:1(0) ack 10001 win 257 |
| +0 %{ |
| assert tcpi_ca_state == TCP_CA_Open, tcpi_ca_state |
| assert tcpi_unacked == 0, tcpi_unacked |
| assert tcpi_sacked == 0, tcpi_sacked |
| assert tcpi_lost == 0, tcpi_lost |
| assert tcpi_retrans == 0, tcpi_retrans |
| }% |
